Device for sucking additives into a fluid stream

ABSTRACT

The invention involves an apparatus for the induction and admixture of additives into a fluid stream by means of a joining piece, whereby a plug projects into the fluid stream and blocks a major part of the stream cross-section. This plug exhibits, in the area of the flow-through gap, an opening that is joined with a connecting conduit for the additive that is to be inducted. It is fundamental that the gap cross-sections for the fluid steam on both sides of the plug are of differing sizes.

FIELD OF THE INVENTION

The invention involves an apparatus for the induction and admixture ofadditives into a fluid stream by means of a joining piece that exhibitsa through conduit for the fluid and a connecting conduit, which isjoined with the through conduit, for the additive, whereby the additiveis inducted by means of a negative pressure that is generated by thefluid stream, while a plug projects into the through conduitapproximately transversely to the fluid stream, and this plug blocks amajor part of the fluid stream, however, it can be bypassed by the flowto the side, longitudinally, through at least one gap, and at that placeexhibits at least one opening that is joined with the connecting conduitfor the additive.

BACKGROUND OF THE INVENTION

An apparatus of such a type is known through DE-OS 39 30 709 from thesame applicant. It is distinguished by surprisingly high suction powerat the connecting conduit for the additive, so that even the admixtureof viscous, gelatinous media of high viscosity is assured. As the fluidin this regard, basically any liquid or gaseous medium comes intoconsideration.

Studies by the applicant have shown that suction action abates if thefluid that has been mixed with the additive must subsequently overcomehigh flow resistances, that is, if high back pressures downstream of themixing apparatus have to be taken into account. In practice, thisoccurs, for example, if downstream of the mixing apparatus the fluid isto be atomized into the atmosphere or into a combustion chamber by meansof fine jets.

SUMMARY OF THE INVENTION

Beginning from this point, the task of the invention lies in furtherimproving the apparatus described at the beginning with respect to itssuction power. In doing this, it should also be distinguished through astrong negative pressure at the connecting conduit for the additive,even if there are high back pressures. If, for example, an admissionpressure of 6 bar is being used in the fluid, then the apparatus inaccordance with the invention should tolerate a back pressure of 4 to 5bar without the suction power abating significantly.

The resolution of this task succeeds in accordance with the invention byvirtue of the fact that the gap cross-section for the fluid stream isselected in differing sizes at the two sides of the plug, andspecifically, so that the gap cross-section on one side of the plug is,at the most, half as large as the one on the other side of the plug, andin the limit case, even approximately zero.

With this asymmetric arrangement, it has been shown, surprisingly, thatthe suction power is even higher than with the known apparatus describedat the beginning, and that because of that, even higher back pressuresin the outgoing line can be tolerated.

Possibly, this is based on the fact that the smaller flow-through gapprovides for a higher suction power, while the larger flow-through gapallows a high flow-through quantity. If the plug is displaced to theextent that it can still be bypassed by the flow only on one side, then,along with the high suction power, a strong turbulence also appears and,in accordance with that, a good mixing of the fluid and additive aswell.

As was already the case with the apparatus that was previously known,the dimensioning of the gap cross-section is of considerable importancehere as well. It is advisable that the gap cross-section, or the totalof the two cross-sections if the plug is being bypassed by the flow onboth sides, amounts to approximately 5 percent to 8 percent of the fluidconduit cross-section.

In addition, it has proven to be advantageous if the plug exhibits anapproximately round cross-section and projects on one side of the plugtangentially into the through conduit, or cuts into the neighboring wallof the through conduit with an undercut of approximately 1mm--preferably 1/2 mm. In other words, the bore for the plug isdisplaced in a transverse direction relative to the axis of the fluidconduit by approximately 15 to 25 percent relative to the diameter ofthe fluid conduit. When this is done, it has been shown that theformation of dead space at the closed side does not impair the suctionpower in any way, but that, on the contrary, the distribution of theadditive in the fluid is improved.

With regard to the openings in the plug for the additive, it isadvisable to displace them, with reference to a transverse plane throughthe fluid conduit along the plug axis, ahead in the flow direction byapproximately 8° to 12°, preferably by approximately 10°.

Another expedient further development of the invention consists in thefact that the plug completely traverses the walls of the through conduitand is fixed in a manner that is always fluid-tight. Depending on thematerial, it can be glued, sealed, soldered or welded. In each case, oneachieves through this fixing of the plug to both sides of the throughconduit a very exact positioning, which is important in maintaining thedesired gap cross-sections.

In a corresponding way, it is also advisable that the plug be securedagainst turning so that the plug can be installed into the joining pieceonly in a position of such a nature that the openings from which theadditive is inducted lie at the correct angle.

The installing of the plug into the joining piece is best done in such away that it is inserted into the joining piece from the side oppositethe connecting conduit for the additive, whereby it can exhibit on thisopposite side a projection that fits into a corresponding recess of thejoining piece.

Finally, it has proven to be beneficial that the joining piece exhibitsin its connecting conduit a valve, consisting of a valve seat and avalve body, the installation position of which is selected in such a waythat, in the event of negative pressure at the opening for the additive,it is loaded in an opening direction, and in the event of positivepressure at the opening for the additive, it is loaded in a closingdirection. In this way, it is ensured that in the event of a possibleblockage in the outgoing line, the fluid does not flow into theconnecting conduit of the additive and cause impurities there.

This is especially important if the fluid that is being used is heatingoil that is to be mixed with air in the joining piece in order toimprove combustion.

For safety reasons, the valve body can in addition be loaded in theclosing direction by means of a spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features and advantages of the object of the application canbe drawn from the following description of an implementation examplewith the aid of the drawing. The following are shown:

FIG. 1 The empty joining piece in an axial section along the throughconduit;

FIG. 2 A cross-section through the line II--II in FIG. 1;

FIG. 3 A bottom view of the joining piece in accordance with FIG. 1;

FIG. 4 An enlarged axial section in accordance with FIG. 1, but with theinstalled parts.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As FIGS. 1 and 4 show in particular, the T-shaped joining piece 1includes a horizontal bore for the through conduit 2, and, emptyingvertically into this conduit, a vertical bore 3 that functions in itsupper portion 3a as a connecting conduit for the additive, while in itslower portion 3b, it serves to seat a plug, which will be discussed inmore detail later.

Now, it is fundamental that the axes of the bores 2 and 3b do notintersect, but are displaced relative to one another. In accordance withFIG. 2, the bore 3b is displaced in a transverse direction in such a waythat it is approximately tangential to the left wall of the throughconduit 2, whereas it cuts approximately 1 to 2 mm deep into the rightwall. As a result, an approximately sickle-shaped gap 4 is createdthere.

If the plug 5 shown in FIG. 4 is now inserted into the joining piece 1from below, then this plug can only be bypassed by the flow on one side,namely, along the gap 4, while the through conduit on the other side ofthe plug is blocked.

The additive is fed in via the connecting conduit 3a. It makes its waythrough a bore 6 in the plug 5 into the inside of the plug, and is theninducted from there and entrained by the fluid via at least one opening7 that has its outlet at the gap 4, and is displaced by approximately 10degrees of angle in the direction of the flow, the direction of flow inconduit 2 being indicated by the phantom arrow in FIGS. 1 and 4.

The upper portion 3a of the bore 3 is reduced in diameter with referenceto the portion 3b while forming a valve seat 8, and bears in itsinterior a valve body 9, which, by means of a sealing ring, operates inconjunction with the valve seat 8. It is able to be moved vertically inthe bore 3a, kept by an annular passage, but is pressed upward into theclosed position by means of a spring 10 that is mounted in the bore 6 ofthe plug 5.

At its upper end, the valve body 9 carries a stop ring 11 that isrotatable on a screw thread. Its clearance with respect to the upper endof the joining piece 1 defines the maximum opening travel of the valvebody 9, and thereby makes it possible to regulate the quantity of theadditive that is inducted by the fluid.

In order to ensure the properly fitting installation of the plug 5 inthe joining piece 1, the plug bears at its lower end an encirclingprojection 12 that--as FIGS. 1 and 2 show--fits into a matching recess1a in the joining piece and is therein secured in a fluid-tight manner.At the same time, a locking piston 12a ensures that the plug can only beinstalled in one specific position, in which the opening 7, relative tothe direction of flow, is slightly displaced in the direction towardsthe outgoing fluid.

In principle, the described apparatus is suitable for all applicationsin which a liquid or a gas is to be mixed into a liquid or gaseousfluid.

Installation in the heating oil supply of burners has proven to beparticularly successful. In this case, the heating oil flows through thethrough conduit 2 and inducts fresh air via the connecting conduit 3a.This fresh air is intensively mixed with the heating oil, whereby theheating oil experiences an intensive preatomization.

The Rhineland TUV [Technical Monitoring Association] has determined thatthe flame temperature increases significantly, and the combustion of theheating oil is improved. Measurements by the Rhineland TUV showed anastonishingly high savings of 10 to 15 percent in heating oil. At thesame time, the emission of pollutants was drastically reduced.

I claim:
 1. Apparatus for the induction and admixture of additives intoa fluid stream by means of a joining piece (1) that exhibits a throughconduit (2) for the fluid and a connecting conduit (3a), which is joinedwith the through conduit, for the additive, whereby the additive isinducted by means of a negative pressure that is generated by the fluidstream, while a plug (5) projects into the through conduit (2)approximately transversely to the fluid stream, and this plug (5) blocksa major part of the fluid stream, however, it can be bypassed by theflow to the side, longitudinally, through at least one gap (4), and atthat place exhibits at least one opening (7) that is joined with theconnecting conduit (3a) for the additive, characterized by the fact thatthe gap cross-sections (4) for the fluid steam on the two sides of theplug (5) are of differing sizes.
 2. Apparatus in accordance with claim1, characterized by the fact that the gap cross-section on one side ofthe plug is, at the most, half as large as the one on the other side ofthe plug.
 3. Apparatus in accordance with claim 1, characterized by thefact that the gap cross-section on one side of the plug is approximatelyzero, and that the gap cross-section (4) on the other side of the plugamounts to approximately 5 to 8 percent of the fluid conduitcross-section.
 4. Apparatus in accordance with claim 1 characterized bythe fact that the plug (5) exhibits an approximately roundcross-section, and on one side of the plug projects tangentially intothe through conduit (2) for the fluid, while it forms a gap (4) on theother side.
 5. Apparatus in accordance with claim 1, characterized bythe fact that the plug (5) exhibits an approximately roundcross-section, and at one side of the plug cuts into the neighboringwall of the through conduit with an undercut of approximately 1 mm,while it forms a gap (4) on the other side.
 6. Apparatus in accordancewith claim 5, wherein the undercut is approximately 1/2 mm.
 7. Apparatusin accordance with claim 1, characterized by the fact that the opening(7) in the plug (5) is displaced, with reference to a transverse planethrough the through conduit (2) along the plug axis, ahead in the flowdirection by approximately 8° to 12°.
 8. Apparatus in accordance withclaim 1, characterized by the fact that the plug (5) completelytraverses the walls of the through conduit (2) and is fixed in a mannerthat is always fluid-tight.
 9. Apparatus in accordance with claim 1,characterized by the fact that the plug (5) is secured against turningby a positive-fit engagement (12a) with the joining piece (1). 10.Apparatus in accordance with claim 1, characterized by the fact that theplug (5) can be inserted into the joining piece (1) from the sideopposite the connecting conduit (3a) for the additive.
 11. Apparatus inaccordance with claim 1, characterized by the fact that the plug (5)exhibits on the side opposite the connecting conduit (3a) an encirclingprojection (12) that fits into a matching recess (1a) in the joiningpiece (1).
 12. Apparatus in accordance with claim 1, characterized bythe fact that the joining piece (1) exhibits in its connecting conduit(3a) a valve seat (8) and a valve body (9), the installation position ofwhich is selected in such a way that, in the event of negative pressureat the opening (7) for the additive, it is loaded in an openingdirection, and in the event of positive pressure at the opening (7) forthe additive, it is loaded in a closing direction.
 13. Apparatus inaccordance with claim 12, characterized by the fact that the valve body(9) is additionally loaded in the closing direction by means of a spring(10).
 14. Apparatus in accordance with claim 13, characterized by thefact that the spring (10) is accommodated in a bore (6) of the plug (5).15. Apparatus in accordance with claim 12, characterized by the factthat the valve seat (8) is formed directly into the connecting conduit(3a).